Let me explain why I love this LN so much, even though 99.99% of them should only exist to provide scripts to anime/manga.

1. The worldbuilding. My god. The world is ridiculously deep and fleshed out. You have competing interests, 3 factions locked in stalemate due to their bloody war, overall enemies, etc. It's extremely compelling and I'd venture to say that if the author had been writing as long as GRRM did, he would have made a better world. Literally.

2. The lack of a shitty protag. Issei is not a pussy. He can fight, he has a personality, and has most of all a WILL, which is literally his main power. While I still kinda disagree with his non-existent romance capabilities, it's excusable since he has literally no time before the next terror comes along.

3. The plot. This seems like a mindless ecchi romance, but then again, it's rated at 8.6. Kinda hard for a ecchi romance to get there. There is plot. The plot is literally the driving point of the story and it rams it through the mostly bad prose(still lacking in true light novel fashion, but we're not reading this for literary analysis)

Read it. It's long(well over 1 million words) but it's extremely rewarding.